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Wolbachia, a group of Gram-negative symbiotic bacteria, infects nematodes and a wide range of arthropods. Diaphorina citri Kuwayama, the vector of Candidatus Liberibacter asiaticus (CLas) that causes citrus greening disease, is naturally infected with Wolbachia (wDi). However, the interaction between wDi and D. citri remains poorly understood. In this study, we performed a pan-genome analysis using 65 wDi genomes to gain a comprehensive understanding of wDi. Based on average nucleotide identity (ANI) analysis, we classified the wDi strains into Asia and North America strains. The ANI analysis, principal coordinates analysis (PCoA), and phylogenetic tree analysis supported that the D. citri in Florida did not originate from China. Furthermore, we found that a significant number of core genes were associated with metabolic pathways. Pathways such as thiamine metabolism, type I secretion system, biotin transport, and phospholipid transport were highly conserved across all analyzed wDi genomes. The variation analysis between Asia and North America wDi showed that there were 39,625 single-nucleotide polymorphisms (SNPs), 2153 indels, 10 inversions, 29 translocations, 65 duplications, 10 SV-based insertions, and 4 SV-based deletions. The SV-based insertions and deletions involved genes encoding transposase, phage tail tube protein, ankyrin repeat (ANK) protein, and group II intron-encoded protein. Pan-genome analysis of wDi contributes to our understanding of the geographical population of wDi, the origin of hosts of D. citri, and the interaction between wDi and its host, thus facilitating the development of strategies to control the insects and huanglongbing (HLB). [ABSTRACT FROM AUTHOR]

SBP-box is an important plant-specific transcription factor family and is involved in diverse biological processes. Here, we identified a total of 15 SBP-BOX genes in the important fruit crop sweet orange (Citrus sinensis) and characterized their gene structures, conserved domain and motif, chromosomal location, and cis-acting regulatory elements. SBP genes were classified into four subfamilies based on the amino acid sequence homology, and the classification is equally strongly supported by the gene and protein structures. Our analysis revealed that segmental duplication events were the main driving force in the evolution of CsSBP genes, and gene pairs might undergo extensive purifying selection. Further synteny analysis of the SBP members among sweet orange and other plant species provides valuable information for clarifying the CsSBP family evolutionary relationship. According to publicly available RNA-seq data and qRT-PCR analysis from various sweet orange tissues, CsSBP genes may be expressed in different tissues and developmental stages. Gene expression analysis showed variable expression profiles of CsSBP genes under various abiotic stresses, such as high and low-temperature, salt, and wound treatments, demonstrating the potential role of SBP members in sweet orange response to abiotic stress. Noticeably, all CsSBP genes were also downregulated in sweet orange upon the infection of an important fungal pathogen Diaporthe citri. Our results provide valuable information for exploring the role of SBP-Box in sweet orange. [ABSTRACT FROM AUTHOR]

P3N-PIPO (P3 N-terminal fused with Pretty Interesting Potyviridae ORF), the movement protein of potyviruses, is expressed as a translational fusion with the N-terminus of P3 in potyviruses. As reported in previous studies, P3N-PIPO is expressed via transcriptional slippage at a conserved G2A6 slippery site in the genus Potyvirus. However, it is still unknown whether a similar expression mechanism of P3N-PIPO is used in the other genera of the family Potyviridae. Moreover, due to the extremely low expression level of P3N-PIPO in natural virus-infected plants, the peptides spanning the slippery site which provide direct evidence of the slippage at the protein level, have not been identified yet. In this study, a potato virus X (PVX)-based expression vector was utilized to investigate the expression mechanism of P3N-PIPO. A high expression level of the P3N-PIPO(WT) of turnip mosaic virus (TuMV, genus Potyvirus) was observed based on the PVX expression vector. For the first time, we successfully identified the peptides of P3N-PIPO spanning the slippery site by mass spectrometry. Likewise, the P3N-PIPO(WT) of wheat yellow mosaic virus (WYMV, genus Bymovirus) was also successfully expressed using the PVX expression vector. Integrated proteome and transcriptome analyses revealed that WYMV P3N-PIPO was expressed at the conserved G2A6 site through transcriptional slippage. Moreover, as revealed by mutagenesis analysis, Hexa-adenosine of the G2A6 site was important for the frameshift expression of P3N-PIPO in WYMV. According to our results, the PVX-based expression vector might be used as an excellent tool to study the expression mechanism of P3N-PIPO in Potyviridae. To the best of our knowledge, this is the first experimental evidence dissecting the expression mechanism of a bymovirus P3N-PIPO in the experimental host Nicotiana benthamiana. [ABSTRACT FROM AUTHOR]

Simple Summary: Recent studies have shown that a large number of long noncoding RNAs (lncRNAs) can regulate various biological processes in animals and plants. However, the roles of long non-coding RNAs (lncRNAs) in the interaction between plants and viruses is unclear, particularly for the Chinese wheat mosaic virus (CWMV) interaction. In this study, we used a deep RNA sequencing strategy to profile lncRNAs involved in the response to CWMV infection in Nicotiana benthamiana and analyzed differentially expressed lncRNAs that responded to CWMV infection, using a bioinformatics method. We identified 1175 new lncRNAs in N. benthamiana infected with CWMV, with 65 lncRNAs showing differential expression. These lncRNAs were mainly enriched in plant hormone signal transduction and other pathways according to GO and KEGG pathway enrichment analyses. In addition, differential expression of XLOC_006393 after CWMV infection may be the precursor of NbmiR168c, which can respond to CWMV infection by modulating the expression of its target gene NbAGO1. We believe that our study makes a significant contribution to the literature because these results provide a valuable resource for studying lncRNAs involved in CWMV infection and improving the understanding of the molecular mechanism of CWMV infection. Recent studies have shown that a large number of long noncoding RNAs (lncRNAs) can regulate various biological processes in animals and plants. Although lncRNAs have been identified in many plants, they have not been reported in the model plant Nicotiana benthamiana. Particularly, the role of lncRNAs in plant virus infection remains unknown. In this study, we identified lncRNAs in N. benthamiana response to Chinese wheat mosaic virus (CWMV) infection by RNA sequencing. A total of 1175 lncRNAs, including 65 differentially expressed lncRNAs, were identified during CWMV infection. We then analyzed the functions of some of these differentially expressed lncRNAs. Interestingly, one differentially expressed lncRNA, XLOC_006393, was found to participate in CWMV infection as a precursor to microRNAs in N. benthamiana. These results suggest that lncRNAs play an important role in the regulatory network of N. benthamiana in response to CWMV infection. [ABSTRACT FROM AUTHOR]

The GATA proteins, functioning as transcription factors (TFs), are involved in multiple plant physiological and biochemical processes. In this study, 28 GATA TFs of Brachypodium distachyon (BdGATA) were systematically characterized via whole-genome analysis. BdGATA genes unevenly distribute on five chromosomes of B. distachyon and undergo purifying selection during the evolution process. The putative cis-acting regulatory elements and gene interaction network of BdGATA were found to be associated with hormones and defense responses. Noticeably, the expression profiles measured by quantitative real-time PCR indicated that BdGATA genes were sensitive to methyl jasmonate (MeJA) and salicylic acid (SA) treatment, and 10 of them responded to invasion of the fungal pathogen Magnaporthe oryzae, which causes rice blast disease. Genome-wide characterization, evolution, and expression profile analysis of BdGATA genes can open new avenues for uncovering the functions of the GATA genes family in plants and further improve the knowledge of cellular signaling in plant defense. [ABSTRACT FROM AUTHOR]

Histone acetylation is a dynamic modification process co-regulated by histone acetyltransferases (HATs) and histone deacetylases (HDACs). Although HDACs play vital roles in abiotic or biotic stress responses, their members in Triticumaestivum and their response to plant viruses remain unknown. Here, we identified and characterized 49 T. aestivumHDACs (TaHDACs) at the whole-genome level. Based on phylogenetic analyses, TaHDACs could be divided into 5 clades, and their protein spatial structure was integral and conserved. Chromosomal location and synteny analyses showed that TaHDACs were widely distributed on wheat chromosomes, and gene duplication has accelerated the TaHDAC gene family evolution. The cis-acting element analysis indicated that TaHDACs were involved in hormone response, light response, abiotic stress, growth, and development. Heatmaps analysis of RNA-sequencing data showed that TaHDAC genes were involved in biotic or abiotic stress response. Selected TaHDACs were differentially expressed in diverse tissues or under varying temperature conditions. All selected TaHDACs were significantly upregulated following infection with the barley stripe mosaic virus (BSMV), Chinese wheat mosaic virus (CWMV), and wheat yellow mosaic virus (WYMV), suggesting their involvement in response to viral infections. Furthermore, TaSRT1-silenced contributed to increasing wheat resistance against CWMV infection. In summary, these findings could help deepen the understanding of the structure and characteristics of the HDAC gene family in wheat and lay the foundation for exploring the function of TaHDACs in plants resistant to viral infections. [ABSTRACT FROM AUTHOR]

Brachypodium distachyon, as an effective model of cereal grains, is susceptible to most destructive cereal pathogens. Senescence associated gene 101 (SAG101) has been studied extensively in Arabidopsis. SAG101 is one of the important regulators of plant immunity. However, no homologous genes of AtSAG101 were found in B. distachyon. In this study, the AtSAG101 gene was transformed into B. distachyon. Three transgenic plant lines containing the AtSAG101 gene were confirmed by PCR and GUS gene activity. There were fewer Puccinia brachypodii urediospores in the AtSAG101-overexpressing plants compared to wild type plants. P. brachypodii biomass was obviously decreased in AtSAG101 transgenic plants. The length of infection hyphae and infection unit areas of P. brachypodii were significantly limited in transgenic plants. Moreover, there were small lesions in AtSAG101 transgenic plants challenged by Magnaporthe oryzae. Salicylic acid accumulation was significantly increased, which led to elevated pathogenesis-related gene expression in transgenic B. distachyon inoculated by P. brachypodii or M. oryzae compared to wild type plants. These results were consistent with infected phenotypes. Overexpression of AtSAG101 in B. distachyon caused resistance to M. oryzae and P. brachypodii. These results suggest that AtSAG101 could regulate plant resistance in B. distachyon. [ABSTRACT FROM AUTHOR]

P3N-PIPO (P3 N-terminal fused with Pretty Interesting Potyviridae ORF), the movement protein of potyviruses, is expressed as a translational fusion with the N-terminus of P3 in potyviruses. As reported in previous studies, P3N-PIPO is expressed via transcriptional slippage at a conserved G 2 A 6 slippery site in the genus Potyvirus . However, it is still unknown whether a similar expression mechanism of P3N-PIPO is used in the other genera of the family Potyviridae . Moreover, due to the extremely low expression level of P3N-PIPO in natural virus-infected plants, the peptides spanning the slippery site which provide direct evidence of the slippage at the protein level, have not been identified yet. In this study, a potato virus X (PVX)-based expression vector was utilized to investigate the expression mechanism of P3N-PIPO. A high expression level of the P3N-PIPO(WT) of turnip mosaic virus (TuMV, genus Potyvirus ) was observed based on the PVX expression vector. For the first time, we successfully identified the peptides of P3N-PIPO spanning the slippery site by mass spectrometry. Likewise, the P3N-PIPO(WT) of wheat yellow mosaic virus (WYMV, genus Bymovirus ) was also successfully expressed using the PVX expression vector. Integrated proteome and transcriptome analyses revealed that WYMV P3N-PIPO was expressed at the conserved G 2 A 6 site through transcriptional slippage. Moreover, as revealed by mutagenesis analysis, Hexa-adenosine of the G 2 A 6 site was important for the frameshift expression of P3N-PIPO in WYMV. According to our results, the PVX-based expression vector might be used as an excellent tool to study the expression mechanism of P3N-PIPO in Potyviridae . To the best of our knowledge, this is the first experimental evidence for the expression mechanism of P3N-PIPO in the genus Bymovirus , the only genus comprising bipartite virus species in the family Potyviridae .